Email: physiology@rosalindfranklin.edu Fax: 847.578.3265
Hawkins, Richard A Kim, Donghee
Najmabadi, Feridoon McCormack, Charles E. Peterson, Darryl R. Rasgado-Flores, Hèctor
We study the transport of essential nutrients across the blood-brain barrier using methods in vitro (e.g., isolated cell constituents) and in vivo (e.g., autoradiography). Currently, we are focusing on glucose and amino acid carriers in the constituent membranes of the blood-brain barrier, as well as those in intracellular pools. Both the luminal and abluminal membranes of endothelial cells, which constitute the blood-brain barrier, are isolated as vesicles, and various measurements made. We are testing the hypothesis that the distribution, ion dependency, and kinetics of transport proteins favor the delivery of glucose and essential amino acids to the brain, but prevent accumulation of nonessential amino acids that serve as neurotransmitters. Currently we are concentrating on: 1) Determining the distribution and transport kinetics of glucose carriers in the luminal and abluminal membranes of endothelial cells and their relationship with intracellular carrier pools, and 2) Determining the distribution and transport kinetics of neutral amino acid carriers in the individual membranes of the blood-brain barrier.
O’Kane, R.L. Viña J.R., Simpson I.A. and Hawkins, R.A.: Na+-dependent neutral amino acid transporters (A, ASC and N) of the blood-brain barrier: mechanisms for neutral amino acid removal. American Journal of Physiology Endocrinology andl Metabolism. 2004 May 27 [Epub ahead of print] PMID: 15165996
O’Kane, R.L. and Hawkins, R.A.: A Na+-dependent carrier of large neutral amino acids exists at the abluminal membrane of the blood-brain barrier. American Journal of Physiology, 285:E1167-E1173. 2003
Hawkins, R.A., Peterson D.R. and Viña J.R. The complementary membranes forming the blood-brain barrier. IUBMB Life, 54:101-107, 2002.
Simpson I.A., Vannucci S.J., DeJoseph M.R., and Hawkins R.A. Glucose transporter asymmetries in the bovine blood-brain barrier Journal of Biological Chemistry, 20; 276(16):12725-9. 2001.
O’Kane, R.L., Martinez-Lopez, I., DeJoseph, M.R., Viña, J.R., Hawkins, R.A. Na+-dependent glutamate transporters (EAAT1, EAAT2, and EAAT3) of the blood-brain barrier. A Mechanism for glutamate removal. Journal of Biological Chemistry, 274:31891-31895, 1999.
Lee, W-J., Hawkins, R.A., Viña, J.R., and Peterson, D.R. Glutamine transport by the blood-brain barrier: a possible mechanism for nitrogen removal. American Journal of Physiology, 274: C1101-C1107, 1998.